Mitsubishi Electric HD-4001 User manual

CAUTION:
Before servicing this chassis, it is important that the service person read the "SAFETY PRECAUTIONS" and
"PRODUCTSAFETYNOTICE"containedinthismanual.
• Design specifications are subject to change without notice.
MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC.
9351JeronimoRoad,Irvine,CA 92618-1904
Copyright © 2005 Mitsubishi Digital ElectronicsAmerica, Inc.
AllRights Reserved
MITSUBISHIELECTRIC
SerSer
SerSer
Servicevice
vicevice
vice
ManualManual
ManualManual
Manual
20052005
20052005
2005
SET TOP BOX
V26K CHASSIS
SPECIFICATIONS
• Power Input : AC 120V, 60Hz
•Power Usage :82W
• Frequency Range : VHF 54 ~ 470MHz
UHF 470 ~ 806MHz
Analog Cable - 1 ~ 125
Digital Cable - 1 ~ 135
•Antenna Input : 2 RF 75Ω unbalanced
• Tuning : 1NTSC/ATSC/QAM
1 CableCARD™ Slot
1 NTSC for PIP
• Cabinet Dimensions : 17"(W) x 3.7"(H) x 17.25"(D)
• Weight : 12.8 lbs
• Analog Input : VIDEO IN JACK (RCA Type)
Levels 1.0Vp-p 75Ω unbalanced
: AUDIOINJACK (RCAType)
-4.7dBm 43kΩunbalanced
: S-VIDEOINJACK
(Y/C separate type)
Y:1.0 Vp-p C:0.286Vp-p(BURST)
75Ω unbalanced
: COMP/Y, Cr,Cb (RCAType)
Y: 1.0 Vp-p Cr, Cb: 700mVp-p
• Output Level : VIDEOOUTJACK(RCAType)
1.0Vp-p 75Ω unbalanced
: AUDIOOUT JACK (RCAType)
-4.7dBm 4.7kΩ unbalanced
• Digital : IEEE-1394 I/O Jacks
Interface : AC-3 Digtal Audio Output
:HDMI™ Input
: MonitorLinkTM Control/RS-232C
: CableCARD™ Slot
: NetCommand®
.
MODEL
HD-4001
RECEIVER/CONTROLLER
FOR MODELS LT-3280 & LT-3780

MODEL: HD-4001
Page 3
INTRODUCTION ................................................................................................................................5
PRODUCTSAFETYNOTICE ............................................................................................................. 5
SAFETYPRECAUTIONS ...................................................................................................................6
PWB-LOCATIONS .............................................................................................................................7
DISASSEMBLY ..................................................................................................................................8
TopCoverremoval ..................................................................................................................8
PWB-SIGNAL& PWB-TERMINALRemoval...........................................................................9
SignalBracket Removal ....................................................................................................... 10
RearPanelRemoval............................................................................................................. 11
CardReader Removal&Front PanelRemovall ..................................................................... 12
ELECTRICALADJUSTMENTS ........................................................................................................ 13
Equipment .................................................................................................................................... 13
Option Menu / Initialization Defaults /AV Defaults ......................................................................... 14
LED Diagnostics ........................................................................................................................... 15
RemoteControl OperationalMode ................................................................................................ 15
CircuitAdjustment Mode ............................................................................................................... 16
Transferingdata ............................................................................................................................ 17
Adjustment Items List................................................................................................................... 17
AdjustmentProcedures ................................................................................................................ 18
Test Points .......................................................................................................................... 18
Main-YGain......................................................................................................................... 18
Sub-YGain .......................................................................................................................... 19
SubPictureOffset ............................................................................................................... 19
CHIPPARTS REPLACEMENT ......................................................................................................... 20
REPLACEMENTPARTS .................................................................................................................. 21
PartsOrdering .............................................................................................................................. 21
CriticalandWarranty Parts Designation........................................................................................21
PartsTolerance Codes.................................................................................................................. 21
SERVICE PARTS LIST .................................................................................................................... 22
CIRCUITRYBLOCK DIAGRAMS ..................................................................................................... 31
StandbyPowerSupplies ............................................................................................................... 31
PWB-DM PowerSupplies ............................................................................................................. 32
PWB-SIGNALSwitchedPowerSupplies ...................................................................................... 32
Tuners &Analog Video Select Circuitry......................................................................................... 33
Digital Video Signal Path .............................................................................................................. 34
Sync Signal Selection................................................................................................................... 35
Sync Signal Output Path .............................................................................................................. 35
SoundSignalPath ........................................................................................................................ 36
Control Circuitry ............................................................................................................................ 37
CommandInput Circuitry............................................................................................................... 38
MacrovisionDetection ................................................................................................................... 38
CONTENTS

Page 4
MODEL: HD-4001
Part 2
Schematic Diagrams
CONTENTS Page
SCHEMATICDIAGRAMS
OverallPWB Interconnect Diagram .................................................................................................1
POWER / E2P / CONTROL / MV Decoder] ....................................................................................2
TERMINAL-1/ TERMINAL-2 [Inputs / Outputs] ...............................................................................3
SIGNAL-1[VideoSwitch]................................................................................................................4
SIGNAL-2[Decoder/Switch]..........................................................................................................5
SIGNALS-3[Micro} .........................................................................................................................6
SIGNAL-4[TVGO] ..........................................................................................................................7
SIGNAL-5[MPEGEncoder]............................................................................................................8
SIGNAL-6[HDMIRX] ...................................................................................................................... 9
SIGNAL-7[HDMITX]..................................................................................................................... 10
SIGNAL-8[Video Output]............................................................................................................. 11
SIGNAL-9[IR232] ......................................................................................................................... 12
TUNER-1[ATSC/NTSCTuner] .................................................................................................... 13
TUNER-2[MainATSC/ NTSC Demodulators] ............................................................................... 14
PWB LAYOUT DIAGRAMS .............................................................................................................. 15

MODELS: HD-4001
Page 5
INTRODUCTION
Thisservice manual providesservice instructions for STBmodel HD-4001which usesthe V26Kchassis. Service
personnelshould read this manualthoroughly before servicingthese chassis.
Thisservice manual includes:
1. SafetyPrecautions
2. Assembly and disassembly instructions.
3. Servicingprintedcircuitboards(PCBs).
4. Electrical adjustments.
5. Chipparts replacement procedures.
6. Circuitpathdiagrams.
The parts list section of this service manual includes:
1. Cabinetandscreenparts.
2. Electrical parts.
Schematicand block diagramsof theabove listedmodels areincluded inthis servicemanual forbetter understanding
of the circuitry. PCB drawings are also included for easy location of parts and test points.
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in television receivers have special safety related characteristics. These charac-
teristics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by
usingreplacement components rated for highervoltage, wattage, etc.
Replacementparts which havespecial safetycharacteristics areidentified inthis servicemanual.
Electrical components having such features are identified by shading on the schematic diagrams and by bold type in
the parts list of this service manual. and by marking on the supplementary sheet for this chassis to be issued subse-
quently. The replacement for any safety part should be identical in value and characteristics.
CableCARDisatrademark of CableTelevisionLaboratories, Inc.
TVGuideOn Screen isa registered trademarkof GemstarDevelopment Corp.
HDMIisatrademarkof HDMI Licensing, LLC.

Page 6
MODELS: HD-4001
SAFETY PRECAUTIONS
NOTICE: Observe all cautions and safety related notes located inside the receiver cabinet and on the
receiverchassis.
WARNING:
1. Operationofthis receiver outside the cabinet or withthe cover removed presents ashock hazard
fromthe receiver's power supplies. Workon the receivershould notbe attempted byanyone who is
notthoroughlyfamiliarwiththeprecautions necessary when working on high voltage equipment.
2. Whenserviceis required, observe the originallead dress. Extra precautionshould be taken to
assure correct lead dress in the high voltage area. Where a short-circuit has occurred, replace those
componentsthat indicate evidence of overheating.
Leakage current check
Before returning the receiver to the customer, it is recommended that leakage current be measured according to the
followingmethods.
1. Cold Check
With the alternating current (AC) plug removed from theAC source, place a jumper across the twoAC plug
prongs. Connect one lead of an ohm meter to theAC plug and touch the other lead to each exposed metal part
(i.e. antennas, handle bracket, metal cabinet, screw heads, metal overlay, control shafts, etc.), particularly any
exposed metal part that has a return path to the chassis. The resistance of the exposed metal parts having a
return path to the chassis should be a minimum of 1Mega Ohm.Any resistance below this value indicates an
abnormalcondition and requires corrective action.
2. Hot Check ...Use the circuit shown below to perform the hot check test.
1. Keep switch S1 open and connect the receiver to the measuring circuit. Immediately after
connection,andwith the switching devices of thereceiver in their operatingpositions, measure
the leakage current for both positions of switch S2.
2. Close switch S1, energizing the receiver. Immediately after closing switch S1, and with the
switchingdevicesofthe receiver in their operating positions, measurethe leakage current for both
positions of switch S2. Repeat the current measurements of items 1 and 2 after the receiver has
reached thermal stabilization. The leakage current must not exceed 0.5 milliampere (mA).

MODELS: HD-4001
Page 7
PWB-LOCATION
PWB
CONTROL PWB
POWER
FAN
PWB CARD
READER
PWB-SIGNAL
(Top)
PWB
TERMINAL1
PWB-DM
(Under Signal)
PWB
TERMINAL2
PWB
TUNER

Page 8
MODELS: HD-4001
DISASSEMBLY
TOP COVER REMOVAL
Top Cover

MODELS: HD-4001
Page 9
PWB-SIGNAL
PWB
SIGNAL
PWB
TERMINAL1
PWB
TERMINAL2
TERMINAL-PWB
REMOVAL
SIGNAL-PWB
REMOVAL

Page 10
MODELS: HD-4001
SIGNAL BRACKET REMOVAL
SIGNAL
BRACKET
PWB
Support
Post
FAN